Sunday, November 16, 2014

Towards a Sustainable Energy Future

My presentation for the ERM
Alumni Conference on Energy and Natural Resources Policy, Brandenburg
Technical University of Cottbus, Germany, 6-10.10.2008

Abstract: The
world of fossil fuel – based economy is eventually coming into crisis
as these fuels go exhausted. Moreover, the problem is not only the
depletion of these fuels, but also many environmental and social issues
related such as environmental pollution, climate change, oil wars…
Nuclear power cannot be a favourable alternative because of safety and
security challenges of the unsolved nuclear waste problem and the
nightmare of nuclear weapon proliferation. For a sustainable energy
future, we have abundance of renewable energy potential and we should
improve more our energy efficiency in all aspects from technology,
manufacturing, building to daily life consuming.
1. Introduction

Every living-thing needs energy to maintain their lives on Earth.
Everything needs energy to do their works. Every society needs energy to
power their social and economic activities. In anytime and anywhere,
energy is always essential as a heart of matter. However, most present
trends in energy indicate a deteriorating picture.

To some extent, the history of human development has intimately related
to the inventions of energy sources. For a long time in human history,
people had relied mainly on natural energy sources like sunshine,
windmill, water-flow, firewood and animal work. Up until just two recent
centuries, along with industrial revolution, fossil fuels have been
exploited and have quickly become dominant, accounting for approximately
80% of world primary energy consumption [1]. Pressure of
industrialization and population on energy demand has increased
dramatically. Within a rather short time of two hundreds years, we human
have already burnt out an amount of fossil fuels that nature processes
had taken millions of years to form! Obviously, these non-renewable
energy sources will run out someday, and according to some estimate,
that day will not be so far from now for oil. Actually, we are in the
time of Peak Oil, the point when the maximum rate of global petroleum
extraction is reached, after which the rate of production enters
terminal decline [2]. The time of cheap oil will end soon [3]. Many
experts have been warning about the end of our civilization as we know
it is today [4], the end of oil age with its catastrophic consequences
[5]. The world of fossil fuel – based economy is eventually coming into
crisis as these fuels go exhausted. In searching for more energy
resources, people even have fought each other in oil wars. The energy
matter then has turned into serious political matter. Moreover, the
problem is not only the depletion of these fuels, but also many
environmental and social issues related to this type of our fossil
fuel-based economy, such as too much external-dependent, unsustainable
agriculture systems, coal mining risk, offshore oil spillage, pollution
from coal-power plants, from transportation and industrial
activities…and the most serious one perhaps is the green house effect
that leads to global climate change with numerous unpredictable
sub-consequences.

Then, recently, the challenge of climate change has brought up again the
interest in nuclear energy. But ‘Is nuclear the answer?’ [6], the
Sustainable Development Commission in UK conducted eight detailed
studies covering safety, waste, economics and climate change and
concluded that the advantages of nuclear power as a low-carbon
technology are outweighed by disadvantages such as uncertain costs,
long-lived radioactive waste and an increased risk that nuclear weapons
will proliferate. Also, even when considering nuclear power as an option
to meet future energy needs, report from MIT finds: ‘the prospects for
nuclear energy as an option are limited by four unresolved problems:
high relative costs; perceived adverse safety, environmental, and health
effects; potential security risks stemming from proliferation; and
unresolved challenges in long-term management of nuclear wastes’ [7].
Another report from Oxford Research Group [8] has raised two main
questions ‘How dangerous is nuclear power?’ and ‘Can it help reduce CO2
emissions?’ In the report, the short answer to the first questions is
‘very’ - nuclear power is uniquely dangerous when compared to other
energy sources; and for the second question the answer is ‘not enough
and not in time’. Therefore, nuclear power is more a problem than a
solution. On the other hand, uranium is finite resource; that means
ultimately, they will be exhausted someday and thus, like fossil fuels,
it can not be a good answer in the long run.

Then, what are the strategies to tackle this global energy crisis, and further, to achieve a sustainable energy future?

2. Saving energy and improving energy efficiency

The first and foremost available solution is energy conservation,
through reducing energy waste and increasing energy efficiency. We
should recognize the fact that in the mean time alternative energies can
not replace fossil fuels at the scale, rate and manner at which the
world currently consumes them. Moreover, Fritjof Capra [9] pointed out
that the deepest roots of our current energy crisis lie on the patterns
of wasteful production and consumption. Therefore, to solve the crisis,
what truly matters is not getting more energy, which would only
aggravate our problems, but profound changes in our values, attitudes
and lifestyle. Energy conservation is our short-term key energy source
and will always be a good answer in the long run.

Though Peak Oil can conceive quite catastrophic potential, it also opens
some hopeful possibilities, a chance to address many underlying social
problems, and the opportunity to return to simpler, healthier and more
community oriented lifestyle [3]. The example of Cuba can serve as a
positive and instructive model for a world facing Peak Oil on a global
scale [10]. Cuba is the only country that has faced such a crisis – the
massive reduction of fossil fuels, after the Soviet Union collapsed in
1990. Cuba's transition to a low-energy society has taken place by
creating cycling culture, sharing public transportation and turning from
a mechanized, industrial agricultural system to one using organic
methods of farming and local, urban gardens. Lesson from Cuba’s survival
gives us hope in the power of community, and the effectiveness of their
strategies, which can be summarize in three words: curtailment,
conservation and cooperation [11].

Energy conservation brings many benefits. It is low cost and available
at all levels. Using less energy resource also means reducing pollution
and environmental degradation, while prolong fossil fuel supplies and
buying time to phase in renewable energy. Efficiency improvements
efforts include more efficient utilization of both quantity and quality
of energy, as well as broader measures such as improved energy
management, fuel substitution, and better matching of energy carriers
and energy demands [12]. Saving energy can start just right at each
individual’s lifestyle. For examples:

- Buy and use energy-efficient devices
- Look for electronics that are rechargeable
- Turn off and unplug lights, TV sets, computers, and other electronic equipment when they are not in use
- Walk or cycle for short trips, consider car-pooling or take public transport for longer ones
- Live as close to work as possible
- Eat lower on the food chains, buy regionally and seasonally produced organic food whenever possible
The list goes on… and every bit can help.

Many measures can also be done on the technical sphere, where there is a
lot of space expected for creative innovations. In housing, remarkable
energy-saving can be achieved by improved heat insulation or building
design which takes advantages of natural elements like sun, wind,
plants, trees, green-roofs… instead of using air conditioning. Many
intelligent lighting systems with energy-saving sensors have become
widely used for hotels, official buildings. In transportation,
energy-saving techniques can be attained through increasing fuel
efficiency and making vehicles from lighter and stronger materials.
Besides, idea of co-generation, producing both heat and electricity from
one energy source can be well applied in industry.

In addition, a thoughtful vision is needed for energy policy.
Governments should accept a target of phasing out oil and gas use within
50 years, discontinuing all direct and indirect subsidies to the oil
and gas industry, at the same time increasing investment in public
transport, changing tariff policies to support local consumption of
goods produced locally, and encouraging sustainable agriculture [13].
Many policies available to alleviate energy insecurity can also help to
mitigate local pollution and climate change, as a “triple-win” outcome
[14]. For examples, development in public transportation does not only
conserve energy, but also relieve congestion, improve air quality,
provide access for all ages, offer mobility for rural areas [15]. On the
other hand, organic farming does not only reduce petroleum-based inputs
but also improve soil quality, help building healthy land, provide
healthy food for community.

3. Developing renewable energies

Eventually, we will use up non-renewable energy resources. From a
long-term point of view, renewable ones are what we should rely on.
According to the estimation of WBGU (German Advisory Council on Global
Change), we have huge potential of renewable energy sources. All
together, renewable energy sources can provide 3078 times the current
global energy needs, in which solar-power 2850 times, wind-power 200
times, biomass 20 times, geothermal-power 5 times, wave-tidal-power 2
times and hydropower 1 time [16]. Renewable resources, the natural
powers that maintain our lives throughout human history, will not run
out. The Sun shines for all of us, and the wind blows, free of charge.
Although the equipments to collect solar and wind energy, such as solar
panels and wind turbines cost money, when considering that the resource
is taking for free, the overall cost of using solar and wind energy can
make them smart choices. Renewable technology cost trends typically show
a steep decline during last decades [17] and that trends will continue
to reach reasonable levels in the future as their market’s expansion.
Moreover, renewable energy are often clean, such as wind and sunshine,
they do not emit smoke or create pollution. Others, such as biomass,
almost always cause less pollution than fossil or nuclear alternatives.

Renewable energies would bring a number of benefits to the economy.
First, they help increase the diversity of energy supplies, and thus
lower the dependency on imported fossil fuels and improve the security
of energy supplies. Second, they help make use of local resources to
provide a cost-effective energy supply (characterized by mobility,
modularity and low operating costs; renewable energies are very flexible
in case of upgrade and competitive technologies as decentralized
systems) while reducing regional and global greenhouse gas emissions.
Since they are often flexible, small-scale designs, which take the
advantages of local conditions, they can be located close to the demand.
Then, transmission and distribution costs are reduced, as well as
losses. Finally, from the social point of view, renewable energies can
create more domestic employment. Such benefits have created a strong
motivation for pursuing renewable energies in both developed and
developing countries. The investment costs of renewable technologies
have been reduced remarkably today and this makes renewable energies
more attractive, quickly developed and expanded [18].

Solar-power

The Sun has produced energy for billions of years. On average, the
energy from the Sun reaches the Earth is about one kilowatt per square
meter worldwide. Then, in one day, the sunlight which reaches the Earth
produces enough energy to satisfy the world’s current power demands for
eight years. Even though only a percentage of that potential is
technically accessible, this is still enough to provide just under six
times more power than the world currently requires [16]. Unlike other
energy technologies, solar energy technologies cause neither noise, nor
pollution; hence they are often installed near consumers to reduce
construction costs. Solar energy is used for heating water, space,
drying agricultural products, and generating electrical energy.

Besides using design features to maximize use of the Sun (passive solar
systems), some buildings have active systems to gather and store solar
energy as concentrating solar systems (Solar thermal collecting). Solar
collectors sit on the rooftops of buildings to collect solar energy for
space heating, water heating, and space cooling. Most solar collectors
are large flat boxes, painted black on the inside, with glass covers. In
the most common design, pipes in the box carry liquids that take the
heat from the box and bring it into the building. This heated liquid,
usually a water-alcohol mixture to prevent winter freezing, is used to
heat water in a tank or is put through radiators to heat the air.
Interestingly, because of the cooling effect moist air has when it
evaporates, solar heat can also drive a cooling system. By using mirrors
and lenses to concentrate the rays of the Sun, solar thermal systems
produce high temperatures that can be used to heat water for producing
steam to drive an electric turbine or for industrial applications.
Additionally, solar power can contribute to domestic water heating,
which already requires a lot of electricity. Hotels, schools and
hospitals could be equipped with solar water-heating systems.

Photovoltaic (PV, solar cell) systems convert sunlight directly into
electricity. To achieve the desired voltage and current, modules are
wired in series and parallel into PV array. The flexibility of modular
PV system allows designers to create solar power systems that can meet a
wide variety of electrical needs, no matter how large or small. Most of
the market for solar electric today is concentrated in off-grid homes.
Solar cell system is considered as a way to avoid building long and
expensive power lines to remote areas. As the cost of photovoltaic
systems continues to decline, they will find increasingly larger niches.
No other electrical generator is as easy to install or maintain. As PV
prices continue to fall, solar power will become a significant source of
electricity in the 21st century.

On the other hand, just very recently, solar-power has turned to a new
dawn in history as the nanosolar’s thin film technology has been awarded
for “Top Innovation of the Year 2007” by Popular Science magazine [19]
and “Best Invention of the Year 2008” by Time magazine [20]. This
innovation has marked a revolution in solar energy since it utilizes
thin sheets of nonsilicon components that reduce the production costs by
over 90% and decrease the thickness by 99%. The nanosolar powersheet is
thin enough to be rolled and is printable in many versatile forms.
Nanosolar is on track to make solar electricity cost-efficient for
ubiquitous deployment and mass produced on a global scale [21].

Wind-power

Wind is air in motion. It is produced by the uneven heating of the Sun
on the Earth’s surface. Since the Earth’s surface is made of various
land and water formations, it absorbs the Sun’s radiation unevenly. Wind
power turns the kinetic energy of the wind into mechanical or
electrical power which can be used for a variety of tasks. Windmills
have been used for pumping water or grinding grain for hundreds of
years. Today, the windmill's modern equivalent, a wind turbine, can use
the wind's energy to generate electricity. Whether the task is creating
electricity or pumping water, the wind offers an inexpensive, clean and
reliable form of power. Wind energy does not produce any air pollution.
It is completely renewable, and very efficient. It requires minimal
maintenance and has low operating expenses.

Wind turbines can be used as stand-alone applications, or they can be
connected to a utility power grid or even combined with a photovoltaic
(solar cell) system. For utility-scale sources of wind energy, a large
number of wind turbines are usually built close together to form a wind
plant. Small turbines are sometimes connected to diesel/electric
generators or sometimes have a battery to store the extra energy they
collect when the wind is blowing hard. As wind speed doubles, power
generation capability increases eightfold. Wind speed increases with
altitude and over open areas with no windbreaks. Good sites for wind
plants are the tops of smooth, rounded hills, open plains or shorelines,
and mountain gaps that produce wind funneling. Wind energy is growing
fast. It has been the world's fastest growing renewable energy source
for more than a decade with an average annual growth rate of about 25%
along with rapid decline in turbine manufacturing costs. Wind energy is
estimated to grow from 60 GW today (0.5% of global power) to 1000 GW
(12-18% of global power) by 2020 [22]. Wind is free so wind energy can
provide a stable long-term price for power production.

Bio-energy

People have used biomass energy or bio-energy for thousands of years,
ever since people started burning wood to cook food or to keep warm. In
fact, biomass continues to be a major source of energy in much of the
developing world. Biomass is organic material which has stored sunlight
in the form of chemical energy thanks to photosynthetic process of
plants. When burned, the chemical energy is released as heat. Biomass
burning generates about the same amount of carbon dioxide as fossil
fuels, but every time a new plant grows, carbon dioxide is actually
removed from the atmosphere. The net emission of carbon dioxide will be
zero as long as plants continue to be replenished for biomass energy
purposes. These energy crops, such as fast-growing trees and grasses,
are called biomass feedstocks.

In addition to firewood, biomass can be fermentated into liquid form or
extracted from vegetable oils and used in transportation such as ethanol
or biodiesels. Brazil is the leader country in production and
utilization of ethanol from sugarcane. These biofuels produce fewer
emissions than petroleum. However, land use for those energy crops over
food crop planting is still a hard issue, particularly for developing
countries, where the need for food, as the basic need in fighting
poverty, is more predominant.

Biomass fuels include not only wood, straw, plants, residues from
agriculture or forestry, but also the organic component of solid wastes.
Even the fumes from landfills, a byproduct of the decay process of
organic matter in municipal solid waste, comprised of approximately 50%
methane, can be used as a biomass energy source. In fact, landfill gas
has emerged as an easily available, economically competitive and proven
energy source [23]. Reducing landfill methane emission by utilizing it
as a fuel helps capturing a major greenhouse gas 25 times more potent
than carbon dioxide. Obviously, this is a very beneficial approach which
produces energy without competing with food production while
simultaneously solves the problems of waste and protects the
environment. Similarly, biogas is considered one of the cheapest
renewable energies in rural areas in developing countries. Like landfill
gas, it is produced by the action of bacteria on vegetable/organic
material in anaerobic conditions. The bacteria slowly digest the
material (usually animal dung, human wastes and crop residues) and
produce a gas which is roughly 60% methane and 40% carbon dioxide. This
gas is combustible and thus can replace other fuels like wood,
agricultural residues, and kerosene for use in simple gas stoves and
lamps. Biogas is used for cooking, lighting, generating electricity…etc.
Production of biogas would not only save firewood but also be
beneficial for integrated farming systems by converting manure to
fertilizer for crops or ponds for fish and water plants. Other benefits
of biodigestion include the reduction of manure smell, elimination of
smoke when cooking and the alleviation of pathogens and thereby
improving hygiene on farms.

Recently, researchers have brought up a very interesting and good news
for future of biofuel. It is algae, a promising oil alternative, a big
idea for future energy because of its high potential and efficiency
[24]. Since they have simple cellular structure, a lipid-rich
composition and a rapid reproduction rate, these tiny aquatic organisms
can yield 30 times more energy per acre than land crops such as
soybeans, according to the US Department of Energy [25]. Many algae
species also can grow in salt water or other harsh conditions. In
addition, microscopic green algae (pond scum) can split water into
hydrogen and oxygen under controlled conditions [26]. Thus, these green
algae have hopeful potential to become microscopic power plants for
hydrogen, which is considered one of the energy in the future.

Micro-hydropower

Of the renewable energy sources that generate electricity, hydropower is
the most often used. Mechanical energy is derived by directing,
harnessing, or channelling moving water. The amount of available energy
in moving water is determined by its flow or fall. The most common type
of hydroelectric power plant uses a dam on a river to store water in a
reservoir. Water released from the reservoir flows through a turbine,
spinning it, which in turn activates a generator to produce electricity.
But hydroelectric power doesn't necessarily require a large dam. Some
hydroelectric power plants just use a small canal to channel the river
water through a turbine.

Hydropower is almost free, there are no waste products, and hydropower
does not pollute the water or the air. However, it is criticized because
it does change the environment by affecting natural habitats,
especially the ecosystem behind large-scale hydropower dam. So,
small-scale micro-hydro system (pico-hydro system), is more favourable.
Household-scale micro-hydropower systems have proven particularly
important in isolated rural communities that are located far from the
national grid but close to suitable water resources. These pico-hydro,
with a maximum electrical output of 5 kilowatts (kW), sufficient to
power light bulbs, radios, televisions, refrigerators and food
processors [27]. Hydro power systems of this size benefit over the
larger systems in terms of cost and simplicity of design. Only small
water flows are required for pico-hydro systems, meaning that many
suitable sites are likely to exist. A small stream or spring often
provides enough water. Recent innovations in pico-hydro technology have
made it an economic and versatile source of power even in some of the
world's most resource-poor and inaccessible places. Well-designed
pico-hydro systems have a lower cost per kW than solar or wind power.
Pico-hydro equipment is small and compact. The component parts can be
easily transported into remote and inaccessible regions. Local
manufacture is possible, and the design principles and fabrication
processes can be easily learned. The number of houses connected to each
scheme is small, usually under 100 households. This eases maintenance
and reduces capital requirements. Standard AC electricity can be
produced and distributed throughout a village to power electrical
appliances, or it can charge large batteries for households.

4. Future Energy Vision

Several years ago, there was a growing interest in developing a hydrogen
economy [28], which proposed to solve the problems of our current
fossil-fuel-based (hydrocarbon) economy. Hydrogen has been predicted as a
clean energy of the future for stationary, mobile and transport
applications, especially with the use of fuelcells. The main advantage
of hydrogen economy is the elimination of pollution, since the only
byproduct from burning hydrogen or combining hydrogen and oxygen gases
in fuelcell to produce electricity is water vapor, no harmful gases to
environment. In addition, fuelcell-powered vehicles are about twice as
efficient as those with internal combustion engine. During last decade,
fuelcell-vehicles [29] have been developed by many big players in the
world such as Honda, BMW, Huyndai, Toyota, Ford, GM… However, the
development of a hydrogen economy has to face up to major barriers [30]
of producing, transporting and storing hydrogen. The key fact is that
hydrogen is not a source of energy. Like electricity, hydrogen is only
an energy carrier. That means, hydrogen is only a way of storing and
distributing energy, but hydrogen itself has to be generated from
somewhere else. Hydrogen can be produced by electrolysis of water, but
we need electricity to do the work. Moreover, hydrogen is not a
convenient carrier of energy. Because of its lightness and explosive
characteristic, hydrogen containers should be tight enough and quite
bulky. Then, for mobile applicants, hydrogen must be liquefied or
compressed to increase energy density. Therefore, there are still many
difficulties to realize the vision of a hydrogen economy.

On the other hand, since more than fifty years, scientists all over the
world have been working to realize the dream of a fusion vision. There
are now two remarkable fusion projects, both have been developed under
international cooperation: the Joint European Torus (JET) [31] and the
International Thermonuclear Experimental Reactor (ITER) [32]. Fusion,
which is expected to be abundant, clean and safe, could become the
dominant source of electricity on Earth in a century or so. Although it
may be a possible source of energy in the distant future, there is still
a long way to go.

So, what would be the more realistic and feasible prospect for a
sustainable energy future? Lester Brown [33] believes that “the new
energy economy will be based much less on energy from combustion and
more on the direct harnessing of energy from wind, the Sun and the Earth
itself”. Thus, future would belong to the age of Renewable Sources. It
is also the scenario described in the Energy [R]evolution report, by the
European Renewable Energy Council and Greenpeace [16]. The vision would
be made by optimized integration of renewable energy, developing smart
consumption, generation and distribution systems and maximizing the
efficiency of building through better insulation. Solar façade would be a
decorative element on office and apartment buildings. Rooftop wind and
solar would be placed so that energy is generated close to the consumer.
Clean electricity would also come from offshore wind parks or solar
power station in deserts. Electricity would be much more prominent and
become the principal source of energy for transportation, replacing
gasoline and diesel fuels. Hydrogen can become a way of back-up to store
solar, wind energy to use at night or during cloudy days…

Shifting to renewable energy means shifting to more decentralized and
diversified systems which maximize the use of locally available,
environmental friendly energy sources. “It is encouraging to know that
we now have the technologies to build a new energy economy, one that is
not climate-disruptive, that does not pollute air and that can last as
long as the sun itself” – Lester Brown.